Phase II Eastern Washington Equivalent Stormwater Manuals
municipal stormwater permits require
permitted local governments to establish programs that prevent and control the
impacts of runoff from new development, redevelopment and construction sites.
Minimum requirements, thresholds and definitions are in Appendix 1 of the
municipal stormwater permit. In addition, local governments in Eastern
Washington must adopt a site planning process, and criteria for selection and
design of best management practices similar to that described in Ecology’s
Stormwater Management Manual for Eastern Washington.
Eastern Washington Phase II Permittees
have the option of either adopting portions of Ecology’s Stormwater Manual or
portions of a regional manual determined to be equivalent to Ecology’s
Stormwater Manual. We will update this page as additional information becomes
Regional Stormwater Manual
October 8, 2007, The Department of Ecology approved the Spokane County Regional Stormwater Manual
as equivalent to the minimum requirements of the Eastern Washington Phase II
Municipal Stormwater Permit.
Ecology’s approval letter of October 8, 2007
to Spokane County.
Yakima County Regional Stormwater Manual
WSDOT Highway Runoff
Approved for use for WSDOT projects and by local
governments for public road projects
August 20, 2008, the Department of Ecology approved the Washington State
Department of Transportation’s Highway Runoff Manual as functionally equivalent
to the Stormwater Management
Manual for Eastern Washington. The WSDOT manual is designed for and approved
for use only for WSDOT projects and by local governments for public road
for Phase I and Phase II municipal stormwater permit questions
Ecology contacts for technical questions